Atlas of Japan (East) Sea hydrographic properties in summer, 1999

Hydrographic properties from CTD and discrete bottle sample profiles covering the Japan (East) Sea in summer, 1999, are presented in vertical sections, maps at standard depths, maps on isopycnal surfaces, and as property–property distributions. This data set covers most of the Sea with the exception of the western boundary region and northern Tatar Strait, and includes nutrients, pH, alkalinity, and chlorofluorocarbons, as well as the usual temperature, salinity, and oxygen observations.     

Application of wavelet transforms to the decoupling of free-roll decay data

This study presents the results of the decoupling of a free-roll decay test by wavelet transforms. A free-roll decay test was performed to determine the coefficients of damping terms in equations of motion. No motion of the model was restricted during the experiment. A slight yaw motion was found while the model was in the free-roll decay motion. It was necessary to extract a pure roll motion from the experimental data. Wavelet transforms were applied to the signals to extract the pure roll motion. The results were compared to those found through the Fourier transform. Discrete wavelet transforms were able to efficiently decouple the test signals, while the continuous wavelet transform and the Fourier transform could not.     

Effect of native and invasive cordgrass on Macoma petalum density, growth, and isotopic signatures

Ecosystem engineers can influence community and ecosystem dynamics by controlling resources, modifying the flow of energy or biomass, or changing physical characteristics of the habitat. Invasive hybrid cordgrass (Spartina alterniflora × Spartina foliosa) is an ecosystem engineer in salt marshes in San Francisco Bay, California, U.S.A. that raises intertidal elevations and may be either increasing C₄ plant carbon input into food webs or tying up carbon in a form that is not usable by consumers. A manipulative experiment compared abundance, growth, and stable isotope (δ¹³C and δ¹⁵N) composition of the clam Macoma petalum (=M. balthica) among native marsh, hybrid Spartina, and mudflats in central San Francisco Bay. We found higher densities (individuals m⁻²) of M. petalum on mudflats compared to either native or hybrid Spartina (p < 0.001). Macoma petalum shell growth was significantly greater in mudflats than in either vegetation type in 2002 (p = 0.005) but not 2003. Differences in shell growth between native and hybrid Spartina were not significant. Stable isotope results showed differences between habitats in δ¹³C but not δ¹⁵N. Carbon signatures of M. petalum placed in Spartina were much more depleted than the isotopic signature of Spartina. Neither native nor hybrid Spartina appears to be a significant carbon source for M. petalum in San Francisco Bay, and we found no evidence that hybrid Spartina contributes carbon to M. petalum beyond what is provided by S. foliosa, despite the hybrid's much greater biomass. Our results show that loss of mudflat habitat, rather than increased input of C₄ carbon, is the greatest effect of the invasion of hybrid Spartina on M. petalum.     

Preliminary attempt to characterize the rotation of seafloor in the Pito Deep area of the Easter Microplate using a submersible magnetometer

Several mechanisms have been proposed to account for the rotation of the nearly north-south abyssal hill fabric formed on the East Pacific Rise north of the Easter Microplate to the nearly east-west trends in the northern microplate interior. Proposed mechanisms include rigid microplate rotation, transform fault – parallel shear, and bookshelf faulting during the transfer of lithosphere from the Nazca Plate to the microplate. We used a submersible magnetometer on a NAUTILE dive program to measure the magnetic vector rotation of a pillow basalt and dike spur near Pito Deep, the present location of the tip of the propagating rift system that created the microplate. Our results, although too limited to draw strong conclusions from, suggest clockwise rotations of the seafloor magnetic vectors inconsistent with the transform-parallel shear model, and larger than can be explained solely by rigid microplate rotation.     

Comments on the Gravity and Magnetic Anomalies of Saros Bay using Wavelet Approach

In this paper, residual and regional gravity and magnetic anomalies of Saros Bay are separated using wavelet method. Wavelet is one of the modern, stochastic image approaches processing technique in electronics. The vertical, horizontal and diagonal components of wavelet output are evaluated simultaneously and an underground model is obtained by suitable cross-sections. Thus the geological and tectonic properties of Saros Bay are extracted. Our proposed model is confirmed by deep and shallow seismic researches of Turkish Petroleum Cooperation (TPAO). The South-East region of Saros Graben is formed by strike slip Ganos Fault and Anafartalar reverse Fault that lies on the east of Ganos Fault. On the Northwest region, there is strike slip component fault resulting in the Enez Graben. Here we detected two new oval type geological structure, both of them starting from the Eastern direction of Canakkale Dardanelles and but one of them continuing through Gelibolu Peninsuls, while the other tending to the Enez Graben. We think that these structures are the ruins of a very old sea in this region. This revised version was published online in November 2006 with corrections to the Cover Date.     

Complexation of mercury by dissolved organic matter in surface waters of Galveston Bay, Texas

The chemical speciation of dissolved mercury in surface waters of Galveston Bay was determined using the concentrations of mercury-complexing ligands and conditional stability constants of mercury-ligand complexes. Two classes of natural ligands associated with dissolved organic matter were determined by a competitive ligand exchange-solvent solvent extraction (CLE-SSE) method: a strong class (L_s), ranging from 19 to 93 pM with an average conditional stability constant (K_HgLs) of 10²⁸, and a weak class (L_w) ranging from 1.4 to 9.8 nM with an average K_HgLs of 10²³. The range of conditional stability constants between mercury and natural ligands suggested that sulfides and thiolates are important binding sites for dissolved mercury in estuarine waters. A positive correlation between the estuarine distribution of dissolved glutathione and that of mercury-complexing ligands supported this suggestion. Thermodynamic equilibrium modeling using stability constants for HgL, HgCl_x, Hg(OH)_x, and HgCl(OH) and concentrations of each ligand demonstrated that almost all of the dissolved mercury (> 99%) in Galveston Bay was complexed by natural ligands associated with dissolved organic matter. The importance of low concentrations of high-affinity ligands that may originate in the biological system (i.e., glutathione and phytochelatin) suggests that the greater portion of bulk dissolved organic matter may not be important for mercury complexation in estuarine surface waters.     

The capacity of marine plankton, macrophytes and particulate matter to adsorb Cu in the presence of Mg

A complexometric titration technique was employed to measure the total capacity of a variety of marine organisms to adsorb Cu²⁺. Measured adsorption capacities were 0.22 meq g⁻¹ for phytoplankton, 0.3–1.0 meq g⁻¹ for macrophytes, 1.0–2.5 meq g⁻¹ for zooplankton and 0.3 meq g⁻¹ for suspended particulate matter. The capacity of these materials to adsorb Cu²⁺ was reduced significantly in the presence of Mg²⁺ at seawater concentrations. Competition between Mg^t2+ and Cu²⁺ for adsorption sites at pH 6 is described by an average conditional equilibrium constant of 10^3.7. This constant is such that very little Cu²⁺ may be adsorbed onto particulates and marine phytoplankton in the presence of Mg²⁺. Further, primary productivity data and estimates of the detrital carbon sedimentation in Long Island Sound suggest that the flux of particulate carbon is insufficient to remove significant amounts of Cu from the water column to sediments by adsorption mechanisms.